I dont know what are generating functions. And what means 336?
–
Wyvern666Feb 11 '14 at 18:46

1

$336$ would be the numerator for your probability fraction.
–
John HabertFeb 11 '14 at 18:47

@JohnHabert Well, is very far from the supposed solution.
–
Wyvern666Feb 11 '14 at 18:58

@Wyvern666 I'm not making any claim as to the accuracy of the method. I'm just answering your question about what the $336$ means. If I could answer accurately myself, I would. I leave it to those with more knowledge.
–
John HabertFeb 11 '14 at 19:03